Technika lcd tv

[(*steve*)]

Jonboy, does the screen appear discoloured (typically pink) when it is on, but dull?

If you get a torch and shine it on the screen, can you see any picture at all?

I would not be surprised if its a failure of the backlight or inverter.

 

[Jonboy]

Hi Steve

Thanks for your help....

Pic comes on looking like brightness and contrast were set at minimum - not leaning towards any particular colour. There's not much you can do with a display that only stays on for 2 secs, but have managed to get the menu showing for one of these seconds - that indicates that brightness and contrast are set at about halfway.

No evidence of a picture using the torch trick - there is like a line TB whistle can be heard when the pic disappears.

I haven't opened this thing up yet.... If I did I'd be looking for an EHT tripler/rectifier or line output valve!

Hope that tells you something!

 

[(*steve*)]

Hope that tells you something!

It tells me you're probably older than your picture suggests

It's interesting that you can't detect any image at all when the backlight goes off. That may indicate something more than just the failure of the backlight.

I'm also surprised that you hear a whistle when the backlight goes off. Normally the inverter shuts down and is thus totally quiet. Is it a whistle or a hiss?

I'd probably start by looking at the inverter board and just seeing if there is anything obviously wrong. The voltage is certainly high enough to do nasty tricks.

If you're not getting any picture at all, you may actually have a fault in the power supply to the rest of the TV. If that is shutting down it may be removing the signal that tells the backlight to stay on.

I think my second step would be to check the voltages from the power supply, and possibly have a quick look for any swolen capacitors in it.

 

[Jonboy]

Finally plucked up courage and took the back of this thing - that had the effect of vindicating all the feelings I had back in the year 2001, when I decided to call a halt to my ailing TV repair business.

Anyway... for what it's worth....

Checked the PSU voltages - 5v and 12v. The 12v rail drops to 11.5 when powered up, then comes up to 12v when the backlight goes out - after 2 secs.
Checked the electrolytics in the PSU - 22mfd and 100mfd. Both ok.
Also found a 1000mfd on the inverter board - also ok. (I have a capacitor tester)

It would appear the inverter is receiving a shut down signal for reason or reasons unknown.
Incidently the whistle comes from the PSU when running off-load.

Think it's off down to our local re-cycling plant with this one.
Anyone need a remote?

 

[dtrmad2004]

Hi, I have just picked up one of these Televisions today, hoping for an easy fix so I can use it as a monitor for repairing Xbox 360's

When switched on it makes a low buzzing sound which changes note to a higher pitched buzz before the picture appears then dissappears after 2 seconds like the person before me. It does not buzz when the picture does go off. The picture is not dull.

What I have found from playing with it is that if i press source, down/up then ok the picture will come back for 2 seconds again showing the new selected source then off again, even with a connected source all I get is a blue screen for the short time it does display.

It looks like this has been repaired before because it has a serviced by warranty sticker on the bottom and some components look to have been soldered with also what looks like an extra diode on the underside of the board

I shall get some pictures soon

EDIT: just done a little bit more testing and If i leave it on DVD mode and put a dvd in, it will play and the audio from the dvd can be heard with a little video noise in the audio.

 

[Jonboy]

If you leave it TV mode, does the sound remain on after the picture's gone off?

Also, if watching with the back cover removed do you see the backlight going off after the two seconds has elapsed?

 

[dtrmad2004]

I cannot try TV mode because there is no aerial here, we get our tv from a Virgin cable box that is connected to the normal Tv via HDMI and I tried HDMI with an xbox360 and got no audio when browsing the dashboard blind.

When it is in Analog Tv mode I see the Static but no noise, im not sure if this set mutes the audio when there is no signal?

The backlight goes off when the picture does and have only just noticed if i shine a torch at it I can see a picture, didnt see that when i checked last night.

Since you are tipping your set would you mind selling me your Mainboard so I can try swapping components such as the backlight transformers?

 

[dtrmad2004]

Problem solved.

I got a Universal Inverter for £7 from ebay. http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110559809334&ssPageName=STRK:MEWNX:IT

Read out the 12v, gnd and 5v sources, soldered it up and its working like a champ now

 

[Jonboy]

Nice one, dtrmad... Well done!

I'm pretty sure I've got the exact same fault and the reason I don't see a pic using a torch is because brightness and contrast are set too low.

 

[dtrmad2004]

Thanks.

Well if you want to try it blind, say if its in TV mode, press Tv Menu then down twice then right and left adjusts the brightness. (down once then left right to adjust contrast)

TBH you may have a picture its just you cannot see it, at 1st I couldnt see one untill I tried the a DVD with a static menu picture and could just make it out with a single LED torch but also noticed it was visible in partial sunlight.

 

[Dalesman]

Technika 19" TV - faulty diode

Huh, Ironic I should just stumble across this thread today after spending a good couple of hours yesterday fault finding my LCD191D - 107. However, I too arrived at the conclusion of d102 being the likely culprit. Device confirmed as shorted after removal with my trusty ol' meter.

I ordered myself a replacement off ebay, (slightly cheeper than dalbani by the time you account for P&P)

Ebay item 200395989756 still 3 available for the next 7 days.

Wish my luck I'll let you know the out come if those slackers at the royal mail get around to delivering my diode

Hi All

I followed this advice and got the d102 from Dalbani in Surrey from e-bay. TV has worked fine for 8 months and has fallen over again with same fault. I will try again but part no longer listed on ebay... any suggestions as to where I can get one quickly .. and the full name of the part please?

Thanks

Dalesman

 

[(*steve*)]

If that part is failing, then there's a reason.

Either the part you got from eBay is not quite genuine, or the part chosen is underspecced, or there is another fault causing this part to fail.

One option might be to order a known genuine replacement.

Another might be to get the specs of the part and order something beefier.

If there is another fault causing this problem, it may cause other problems if you eliminate the first point of failure.

 

[martcool]

hi can u help plss i have a techinika lcd19id-107 and its never worked we got it for my nan she put it on and it neve came on from new she never told us untill not years later can i fix this u just hear the power supply clicking away but dont do anythink do u think its the d102 thanks

 

[(*steve*)]

Look here for that diode.

100V 20A schottky diode with an isolated tab.

For more availability look here.

Certainly a lot cheaper than ebay!

 

[martcool]

hi there thanks there are 2 on there are they both the same or do i need to take my one out to c what one i have thanks some one has said to me i need to replace Resistor R110 (5.1 ohm) this gos to when the d102 gos if this helps u thanks

 

[(*steve*)]

I believe both devices listed on Digikey are identical, but they don't have stock. The 2 listed by Mouser seem to differ only in the minimum order (possibly a packaging issue)

What power rating and what package is R110?

 

[martcool]

i dont no all i do no is they both go and its a "5.1 ohm resistor" my one went up to 7.8 so my one was gone but i have replaced it and d102 that was gone too but my one sill not working so what next thanks m8

 

[Tiny1000]

Same TV Different Problem

Hello, I have the same TV power light goes to green, but I found Q101 an 8 leg surface mount IC has blown up!!! Can anyone supply me the number on this IC or a service manual for this model - Thanks

 

[Fertilogue]

Hello All
I am new to this site so please bare with me if I do not follow the correct protocol.
I have a Technika LCD19ID-107-207 combi TV.
The first fault was the DVD player ceased to function. I opened her up and found a blown PCB SM fuse. I replaced it and tested the TV Not only does the DVD player no longer function but I have lost TV as well
Has any-one got a workshop manual for these models? Just a schematic will do. Front light is on stand by and changes to blue when on.
The set reports no signal now when on. Prior to me trying to repair the DVD it worked fine. I have checked I plugged in all the cables. It seems the tuner circuit id no longer functioning.
Thank you for the site and any help that you can give me.

Regards F